Apparatus for rimming paper cups



Feb. 13, 1951 s, w, AMBER@ 2,541,905

APPARATUS FOR RIMMING PAPER CUPS Filed Feb. 6. 1947 Patented Feb. 13, 1951 APPARATUS FOR RIMMING PAPER CUPS Stephen W. Amberg, Barrington, Ill., assignor to Lily-Tulip Cup Corporation, New York, N. Y., a corporation of Delaware Application February 6, 1947, Serial No. 726,870

4 Claims.

This invention relates to an apparatus for forming a rim on the mouth of a conical paper cup.

Heretofore, in the formation of rims on conical paper cups, female and male dies have been utilized. The female die was provided with a conical cavity having a frustro-conical recess and a shoulder therebetween for receiving the cup with the mouth of the cup adjacent the recess. The male die included a conical member conforming to the interior of the cup and having an external shoulder. The male die was inserted axially into the female die with the shoulders ax ially approaching each other to curl the rim between the shoulders. However, the mouth of the paper cup was not confined during the rirnmingl operation with the result that the rim was not uniformly formed and at times the edge of the cup would slip past the shoulder on the male die preventing the formation of a satisfactory rim. Also, it was necessary to maintain the condition of the paper cup, particularly as to moisture content, within prescribed limits to form satisfactory rims in accordance with this method.

The principal object of this invention is to provide an improved method and apparatus for forming a rim on the mouth of a conical paper cup wherein the above difficulties are obviated, wherein the rims are uniformly and consistently formed, and wherein the condition of the paper cup during the rimming operation is not critical. More specifically, an object of this invention is to provide an improved method of forming ya rim on the mouth of a conical paper cup wherein the mouth of the paper cup is confined between an external conical surface, an externally protruding shoulder, and a larger internal conical surface having an internally protruding shoulder and wherein the shoulders are moved toward each other and the spacing between the conical surfaces is maintained substantially constant. In this way the mouth of the paper cup is wholly confined during the rim forming operation so that uniform and consistent rims are assured. Preferably, the shoulders are concave in cross section to assure proper formation of the rims.

Another object of this invention is to provide an improved apparatus for forming rims on the mouths of paper cups in accordance with the foregoing method. and male dies are utilized. The female die has a conical cavity, a frustro-conical recess and a shoulder therebetween for receiving a conical paper cup with the mouth of the cup adjacent the recess. The male die has a plurality of radially In this connection female (Cl. Sli-36.5)

movable slides provided with arcuate tapered guide portions conforming to the contour of the frustro-conical recess, arcuate tapered recess portions conforming to the contour of the interior of the paper cup and shoulders therebetween. The slides are normally extended outwardly. As the male die is moved axially into the female die with a paper cup therebetween, the slides move radially inwardly for forming the rim on the mouth of the paper cup. During the rim forming operation the paper cup is confined between the conical cavity of the female die and the recessed portions of the slides and the mouth of the paper cup is confined between the shoulder and recess of the female die and the shoulders and recessed portions of the slides of the male die as the slides are moved inwardly during the approach of the shoulders. Preferably the slides are held outwardly by springs and are moved inwardly by the engagement of the arcuate tapered guide portions thereof with the frustro-conical recess in the female die as the male die is axially moved.

Other objects and advantages will become apparent to those skilled in the art upon reference to the accompanying specicatien, claims and drawing, in which- Fig. 1 is a vertical sectional view of the male die with the parte in expanded position.

FigA 2 is a vertical sectional view through the female die, the male die and a paper cup therebetween with the parts of the male die in a compressed position;

Fig. 3 is a horizontal sectional view through the male die taken substantially along the line 3-3 of Fig. 1; and

Figs. 4, 5 and 6 are enlarged partial sectional views showing the cooperation between the male die and the female die during the forming of the rim on the mouth of the conical paper cup.

In Figs. 2, 4, 5 and 6, the conical paper cup is designated at I0 and it is provided with a mouth portion l I which is adapted to be rolled into a rim i2 in accordance with the method and apparatus of this invention.

The apparatus for forming the rim on the mouth of the paper cup includes a female die lil having a conical cavity l5 corresponding to the contour of the exterior of the paper cup lil` The upper end of the conical cavity I5 is provided with a frustro-conical recess I6 with a shoulder il therebetween. Preferably the shoulder is concave in cross section, as is illustrated in Figs. 4, 5 and 6. The depth of the shoulder and hence the spacing between the conical surfaces of the cavity l5 and the recess |6 correspond to the thickness of the rim to be formed on the mouth of the paper cup.

The apparatus also includes a male die, generally designated at 26. The male die includes an annular plate 2| secured to a flange 22 of a sleeve 23 by screws 24, The sleeve 23 is in turn rigidly secured to an operating shaft 25 carried by an operator 25. A spring 21 urges the sleeve 23 and hence the plate 2| downwardly with respect to the operator 26 and the downward position thereof is determined by a stop mechanism (not shown) cooperating with the operating shaft 25 and the operator 26. The downward position is illustrated in Fig. 1. As the operator 26 moves downwardly and the downward motion of the sleeve 23 and hence the plate 2| is arrested, the shaft 25 is allowed to move upwardly with respect to the operator 26 against the action of the spring 21, as is illustrated in Fig. 2. Thus there is provided between the shaft 25 and the operator 26 on a one way strain release connection.

The plate 2| is provided with a downwardly extending sleeve portion 29 which is secured to an upwardly extending sleeve portion 30 of an annular spring retainer member 3|. A plurality of radially movable slides 33 are located around the spring retainer 3|. As illustrated, eight such slides 33 are provided. Each of the slides is provided at its end with an arcuate tapered guide portion 34 conforming to the contour of the frustro-conical recess I6 in the female die I4, an arcuate. tapered. recessed portion 35 conforming to the contour of the interior of the paper cup ID, and a shoulder 36 therebetween. Preferably the shoulder 36 is concave in cross section` The slides 33 are provided with extensions 31 between the spring retainer 3| and the plate 2|, and the slides 33 with extensions 31 are sector-shaped. as illustrated in Fig. 3.

The slides 33 are in slidable engagement with the under surface of the plate 2| and the upper surface of the spring retainer 3|, The upper surfaces of the slides 33 are provided with keyways 38 and the lower surfaces of the plate 2| are provided with corresponding keyways 39. Keys 4|! are loosely mounted in the keyways 36 and 39 and operate to limit movement of the slides 33 in a radial direction.

The spring retainer 3| is provided with a series of radial holes 42 for retaining compression springs 43. The compression springs operate to urge the slides 33 radially outwardly against an abutment ring 44 secured to the plate 2| by screws 45. The slides 33 are illustrated in the outward radial positions in Figs. 1 and 3. The slides 33 may be moved radially inwardly against the action of the springs 43 away from the abutment ring 45 and such inward positions of the slides 33 are illustrated in Fig. 2.

The slides 33 are all formed from one piece of metal, annular in shape, which metal piece is turned down to form the conical surface 34, the conical recess 35, and the shoulder 36 therebetween. The contours of the conical surfaces 34 and 35 are made to conform respectively to the contour of the conical recess I6 and the contour of the internal surface of the paper cup I6. After the single metal piece has thus been formed and provided with guideways 31, it is cut into the slides 33, in segment form. and as illustrated in the drawing. eight such slides are cut from the single metal piece.

When the slides 33 thus formed are extended radially by the springs 43, they are spaced apart from each other as illustrated at 46 in Figs. 1 and 3. When the slides are moved inwardly to the position shown in Fig. 2, the spacing between the slides is decreased and the contours of the conical surfaces thereof correspond to the contours of the conical surfaces of the female die and the paper CUD.

The operating shaft 25 is provided with a longitudinal bore 43 for receiving a compression spring 49. The compression spring abuts against a shoulder 5U of a shaft 5| to urge the same downwardly against the plate 2|. The spring 49, however, permits upward movement of the shaft 5I with respect to the plate 2|, thereby providing a one way strain release connection therebetween. The lower end of the shaft 5| is provided with a reduced section 52 for carrying a plunger 53 having a frustro-conical surface 54 conforming to the contour of the interior surface of the paper cup III. The plunger 53 is suitably held on the extension 52 of the shaft 5I by a nut 55.

In the operation of the apparatus thus far described, the operator 26 is elevated to carry with it the male die and the plunger, and a paper cup I0 is inserted in the female die. The paper cup is received in the conical cavity I5 and the mouth II thereof lies adjacent tol the frustroconical recess I6, as is illustrated in Fig. 4. The operator 26 thereupon moves downwardly, carrying with it the plunger 53 and the male die 26. The plunger rst engages the interior of the paper cup I0 for firmly holding the cup in the conical cavity I5 in the female die. Further downward movement of the operator 26 is permitted by reason of the one way strain release connection afforded by the spring 45, although the plunger 53 remains stationary.

After the plunger 53 engages the interior of the paper cup IIJ, the shoulder 26 on the slides 33 engages the the upper edge of the mouth II of the paper cup. as illustrated in Fig. 4, to start rolling the upper edge outwardly. Thereupon the arcuate. tapered guide portions 34 of the slides 33 engage the frustro-conical recess I6 of the female die and as the slides 33 are moved downwardly by the downward movement of the operator 26. the slides 33 gradually move inwardly by reason of the coaction between the surfaces 34 and I5. During this compound movement of the slides 33, the rolling action at the mouth of the paper cup ID is continued, as is illustrated in Fig. 5. When the slides 33 have reached their downward and inward positions, as is illustrated in Figs. 2 and 6, the rim l2 at the mouth of the paper cup Il] is completely formed. Further downward movement of the operator is permitted by the one way strain release connction afforded by the spring 21 between the operator 26 and the plate 2| of the male die.

It is noted that during the entire forming of the rim I2 on the mouth of the paper cup Ill, the material forming the rim is at all times confined between the shoulder I1 and the frustroconical recess I6 ol the female die and the shoulders 36 and the arcuate, tapered, recessed portions 35 of the slides 33. By reason of this confining action the rims I2 must be accurately and consistently formed.

When the rim I2 is thus formed on the mouth of the paper cup I6, the operator 26 moves upwardly carrying with it the male die 20 and the plunger 53 so that the completed paper cup may be removed from the female die and another cup inserted for repetition of the foregoing cycle.

An improved method for forming a rim on the mouth of a conical paper cup is thus provided and it consists of confining the mouth of the paper cup between an external conical surface 35 having an external, protruding shoulder 36 and a larger internalconical surface I6 having an internal protruding shoulder Il. The shoulders are moved toward each other along the conical surfaces by a compound motion, the spacing between the conical surfaces being maintained substantially constant.

While for purposes of illustration one form of this invention has been disclosed. other forms thereof may become apparent to those skilled in the art upon reference to this disclosure, and, therefore, this invention is to be limited only by the scope of the appended claims and prior art.

I claim as my invention:

1. A rimming die for forming a rim on the mouth of a conical paper cup comprising, a female die having a conical cavity. a frustroconical recess and a shoulder therebetween for receiving a conical paper cup with the mouth of the cup adjacent the recess, a male die having radially movable slides provided with arcuate tapered guide portions conforming to the contour of the frustro-conical recess, arcuate tapered recessed portions conforming to the contour of the interior of the paper cup and shoulders therebetween and having means for extending the slides outwardly, and means for moving the male die into the female die and moving the slides inwardly for forming a rim on the mouth of a paper cup inserted therebetween by confining the paper cup between the conical cavity of the female die and the recessed portions of the slides and by confining the mouth of the paper cup between the shoulder and recess of the f I male die and the shoulders and recessed portions of the slides of the male die as the slid 2s are moved inwardly during the approach of the shoulders.

2. A rimming die for forming a rim on the mouth of a conical paper cup comprising, a female die having a conical cavity, a frustro-onical recess and a shoulder of concave cross section therebetween for receiving a conical paper cup with the mouth of the cup adjacent the recess, a male die having radially movable slides provided with arcuate tapered guide portions conforming to the contour of the frustro-conical recess, arcuate tapered recessed portions conforming to the contour of the interior of the paper cup and shoulders of concave cross section therebetween and having means for extending the slides outwardly, and means for moving the male die into the female die and moving the slides inwardly for forming a rim on the mouth of a paper cup inserted therebetween by confining the paper cup between the conical cavity of the female die and the recessed portions of the slides and by confining the mouth of the paper cup between the shoulders and recess of the female die lil and the shoulders and recessed portions of the slides of the male die as the slides are moved inwardly during the approach of the shoulders.

3. A rimming die for forming a rirn on the mouth of a conical paper cup comprising, a female die having a conical cavity, a frustro-conical recess and a shoulder therebetween for receiving a conical paper cup with the mouth of the cup adjacent the recess, a male die having radially movable slides provided with arcuate tapered guide portions conforming to the contour of the frustro-conical recess, arcuate tapered recessed portions conforming to the contour of the interior of the paper cup and shoulders therebetween and having spring means for urging the slides outwardly and stops for limiting the out- Ward movement of the slides, and means for moving the male die into the female die and moving the slides inwardly for forming a rim on the mouth of a paper cup inserted therebetween by confining the paper cup between the conical cavity of the female die and the recessed portions of the slides and by confining the mouth of the paper cup between the shoulder and recess of the female die and the shoulders and recessed portions of the slides of the male die as the slides are moved inwardly against the action of the spring means by the guide portions of the slides engaging the recess of the female die during the approach of the shoulders.

4. A rimming die for forming a rim on the mouth of a conical paper cup comprising, a female die having a conical cavity, a frustro-conical recess and a shoulder therebetween for receiving a conical paper cup with the mouth of the cup adjacent the recess, a male die having radially movable slides provided with arcuate tapered guide portions conforming to the contour of the frustro-conical recess, arcuate tapered recessed portions conforming to the contour of the interior of the paper cup and shoulders therebetween, a plunger for holding a paper cup in the female die, and means for moving the male die into the female die and moving the slides inwardly for forming a rim on the paper cup held in the female die by the plunger by confining the paper cup between the conical cavity of the female die and the recessed portions of the slides and by confining the mouth of the paper cup between the shoulder and recess of the female die and the shoulders and recessed portions of the slides of the male die as the slides are moved inwardly during the approach of the shoulders.

STEPHEN W. AMBERG.

REFERENCES CITED The following references are of record in the le of this patent:

UNITED STATES PATENTS Number 

